For hydraulic hose assemblies and, more generally, for any fluid containing or conveying article, there is a potential risk of leakage of the contained or conveyed fluid. The most critical locations for the appearance of a leakage are connections of two fluid conveying parts, like, for example, at a hose-fitting interface. A leakage can be detect visually when the fluid appears on a surface of the fluid containing or conveying article, for example, on the hydraulic hose or on the fitting.
According to WO 2010/004418 A1, a hose fault detection system includes a hose assembly with a fault detector. The hose assembly includes a first conductive layer, a second conductive layer, and an intermediate layer that is disposed between the first and second conductive layers. The fault detector is configured for detecting a change of an electrical characteristic of at least one of the first and second conductive layers of the hose, which is assumed to be caused by a fault of the hose assembly, for example, when the two conductive layers are short-circuited by leaking fluid.
However, at the moment the leakage can be detected, the fluid either is already in contact with the environment or the contact is at least imminent, such that a potential environmental contamination cannot be obviated. Further, the hose assembly with fault detection is expensive in production with the conductive layers arranged surroundingly and radially spaced to each other. Furthermore, in case of a malfunction of the detection circuit, the complete hose has to be exchanged, in order to restore the fault detection functionality.